Method of making a semiconductor chip assembly with a post/base heat spreader and a substrate using grinding

• US 8,163,603 B2
• Filed: 11/21/2011
• Issued: 04/24/2012
• Est. Priority Date: 03/25/2008
• Status: Expired due to Fees

• Current Assignee: Bridge Semiconductor Corporation
• Original Assignee: Bridge Semiconductor Corporation
• Inventors: Lin, Charles W. C., Wang, Chia-Chung
• Primary Examiner(s): Bryant, Kiesha
• Assistant Examiner(s): BOYLE, ABBIGALE A
• Application Number:
  US13/300,657
• Publication Number:
  US 20120064672A1
• Time in Patent Office: 155 Days
• Field of Search: 438/27, 438/26, 438/122, 438/612, 438/39, 438/759, 438/121, 438/118, 438/464, 438/669, 438/670, 438/677, 438/672, 438/675, 438/690, 438/465, 438/691, 438/22, 438/28, 438/29, 257/684, 257/712, 257/99, 257/707, 257/711, 257/E23.102, 257/E33.075, 257/E33.056
• US Class Current: 438/122
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/32188 the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/85205 Ultrasonic bonding
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 33/483 : Containers
• CPC Class Codes: H01L 33/642 : characterized by the shape
• CPC Class Codes: H05K 1/0204 : using means for thermal conduction connection in the thickness direction of the substrate H05K1/0207 takes precedence
• CPC Class Codes: H05K 2201/09054 : Raised area or protrusion of metal substrate
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]
• CPC Class Codes: H05K 2203/0369 : Etching selective parts of a metal substrate through part of its thickness, e.g. using etch resist
• CPC Class Codes: H05K 3/0061 : onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/386 : by the use of an organic polymeric bonding layer, e.g. adhesive

Abstract

A method of making a semiconductor chip assembly includes providing a post and a base, mounting an adhesive on the base including inserting the post through an opening in the adhesive, mounting a substrate on the adhesive including inserting the post into an aperture in the substrate, then flowing the adhesive between the post and the substrate in the aperture, solidifying the adhesive, then grinding the post and the adhesive, then mounting a semiconductor device on a heat spreader that includes the post and the base, electrically connecting the semiconductor device to the substrate and thermally connecting the semiconductor device to the heat spreader.

Claims

1. A method of making a semiconductor chip assembly, comprising:

providing a post, a base, an adhesive and a substrate, wherein

the substrate includes a conductive layer and a dielectric layer,

the post is adjacent to and integral with the base, extends above the base in an upward direction, extends through an opening in the adhesive and extends into an aperture in the substrate,

the base extends below the post in a downward direction opposite the upward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions,

the adhesive is mounted on and extends above the base, is sandwiched between the base and the substrate and is non-solidified,

the substrate is mounted on and extends above the adhesive, and the conductive layer extends above the dielectric layer, and

a gap is located in the aperture between the post and the substrate;

then

flowing the adhesive into and upward in the gap and above the post and onto a top surface of the post and moving the post upwards in the aperture while flowing the adhesive such that the post extends above the dielectric layer;

solidifying the adhesive;

then

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction, thereby removing the adhesive from the top surface of the post;

then

mounting a semiconductor device on a heat spreader that includes the post and the base, wherein the semiconductor device overlaps the post, a conductive trace includes a pad, a terminal and a selected portion of the conductive layer and the pad is electrically connected to the terminal;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.

2. The method of claim 1, wherein providing the post and the base includes:

providing a metal plate;

forming an etch mask on the metal plate that selectively exposes the metal plate;

etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate; and

then

removing the etch mask, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess, and the base includes an unetched portion of the metal plate below the post and the recess.

3. The method of claim 1, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the substrate; and

solidifying the adhesive includes curing the uncured epoxy.

4. The method of claim 1, wherein flowing the adhesive includes filling the gap with the adhesive.

5. The method of claim 1, wherein providing the pad includes removing selected portions of the conductive layer after grinding the post and the adhesive.

6. The method of claim 1, wherein providing the pad and the terminal includes removing selected portions of the conductive layer after grinding the post and the adhesive.

7. The method of claim 1, wherein providing the terminal includes removing selected portions of the base after grinding the post and the adhesive.

8. The method of claim 1, wherein providing the pad includes removing selected portions of the conductive layer after grinding the post and the adhesive and providing the terminal includes removing selected portions of the base after grinding the post and the adhesive.

9. The method of claim 1, wherein mounting the semiconductor device includes providing a first solder joint between the semiconductor device and the pad and a second solder joint between the semiconductor device and the post, electrically connecting the semiconductor device includes providing the first solder joint between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the second solder joint between the semiconductor device and the post.

10. The method of claim 1, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the post, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the post.

11. A method of making a semiconductor chip assembly, comprising:

providing a post and a base, wherein the post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the post in a downward direction opposite the upward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions;

providing an adhesive, wherein an opening extends through the adhesive;

providing a substrate that includes a conductive layer and a dielectric layer, wherein an aperture extends through the conductive layer and the dielectric layer;

mounting the adhesive on the base, including inserting the post through the opening, wherein the adhesive extends above the base and the post extends through the opening;

mounting the substrate on the adhesive, including inserting the post into the aperture, wherein the substrate extends above the adhesive, the conductive layer extends above the dielectric layer, the post extends through the opening into the aperture, the adhesive is sandwiched between the base and the substrate and is non-solidified, and a gap is located in the aperture between the post and the substrate;

then

applying heat to melt the adhesive;

moving the base and the substrate towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the substrate, wherein the pressure forces the molten adhesive to flow into and upward in the gap and flow above the post and onto a top surface of the post and the post extends above the dielectric layer;

applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the substrate;

then

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction, thereby removing the adhesive from the top surface of the post;

then

providing a conductive trace that includes a pad, a terminal and a selected portion of the conductive layer, wherein the pad is electrically connected to the terminal;

then

mounting a semiconductor device on a heat spreader that includes the post and the base, wherein the semiconductor device overlaps the post;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.

12. The method of claim 11, wherein providing the post and the base includes:

providing a metal plate;

forming an etch mask on the metal plate that selectively exposes the metal plate;

etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate; and

then

removing the etch mask, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess, and the base includes an unetched portion of the metal plate below the post and the recess.

13. The method of claim 11, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the substrate; and

solidifying the adhesive includes curing the uncured epoxy.

14. The method of claim 11, wherein flowing the adhesive includes filling the gap with the adhesive.

15. The method of claim 11, wherein flowing the adhesive and moving the post includes filling the aperture with the post and the adhesive.

16. The method of claim 11, wherein flowing the adhesive includes forcing the adhesive above the conductive layer and onto a top surface of the conductive layer, and grinding the adhesive includes removing the adhesive from the top surface of the conductive layer.

17. The method of claim 11, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface; and

then

etching the conductive layer using an etch mask that defines the pad.

18. The method of claim 11, wherein providing the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface; and

then

etching the conductive layer using an etch mask that defines the terminal.

19. The method of claim 11, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface; and

then

etching the conductive layer using an etch mask that defines the pad and the terminal.

20. The method of claim 11, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

etching the conductive layer using an etch mask that defines the pad; and

etching the base using an etch mask that defines the terminal.

21. The method of claim 11, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad, wherein the pad includes selected portions of the conductive layers and the pad contacts and extends above the dielectric layer.

22. The method of claim 11, wherein providing the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the a top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the terminal, wherein the terminal includes selected portions of the conductive layers and the terminal contacts and extends above the dielectric layer.

23. The method of claim 11, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad and the terminal, wherein the pad and the terminal include selected portions of the conductive layers and the pad and the terminal contact and extend above the dielectric layer.

24. The method of claim 11, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer;

then

etching the conductive layers using an etch mask that defines the pad, wherein the pad includes selected portions of the conductive layers and the pad contacts and extends above the dielectric layer; and

etching the base using an etch mask that defines the terminal, wherein the terminal includes a selected portion of the base that is spaced and separated from and no longer a part of the base and the terminal contacts and extends below the adhesive.

25. The method of claim 11, wherein providing the conductive trace includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

drilling a hole through the adhesive, the conductive layer and the dielectric layer;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer and into the hole, wherein a via includes a portion of the second conductive layer that extends through the adhesive and the dielectric layer in the hole; and

then

providing the pad and the terminal, wherein the pad includes selected portions of the conductive layers and extends above the adhesive and the dielectric layer, the terminal is coplanar with and has the same thickness as the base and extends below the adhesive and the dielectric layer and the conductive trace includes the pad, the terminal and the via.

26. A method of making a semiconductor chip assembly, comprising:

providing a post and a base, wherein the post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the post in a downward direction opposite the upward direction, covers the post in the downward direction and extends laterally from the post in lateral directions orthogonal to the upward and downward directions;

providing an adhesive, wherein an opening extends through the adhesive;

providing a substrate that includes a conductive layer and a dielectric layer, wherein an aperture extends through the conductive layer and the dielectric layer;

mounting the adhesive on the base, including inserting the post into the opening, wherein the adhesive extends above the base;

mounting the substrate on the adhesive, including aligning the post with the aperture, wherein the substrate extends above the adhesive, the conductive layer extends above the dielectric layer, the post extends into the opening and the adhesive is sandwiched between the base and the substrate and is non-solidified;

then applying heat to melt the adhesive;

moving the base and the substrate towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the substrate, wherein the pressure forces the molten adhesive to flow upward in the aperture and flow above the dielectric layer and the post extends above the dielectric layer;

applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the substrate;

then grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then providing a conductive trace that includes a pad, a terminal and a selected portion of the conductive layer, wherein the pad is electrically connected to the terminal;

then mounting a semiconductor device on a heat spreader that includes the post and the base;

electrically connecting the semiconductor device to the conductive trace; and

thermally connecting the semiconductor device to the heat spreader.

27. The method of claim 26, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface; and

then

etching the conductive layer using an etch mask that defines the pad.

28. The method of claim 26, wherein providing the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface; and

then

etching the conductive layer using an etch mask that defines the terminal.

29. The method of claim 26, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface; and

then

etching the conductive layer using an etch mask that defines the pad and the terminal.

30. The method of claim 26, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

etching the conductive layer using an etch mask that defines the pad; and

etching the base using an etch mask that defines the terminal.

31. The method of claim 26, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad, wherein the pad includes selected portions of the conductive layers and the pad contacts and extends above the dielectric layer.

32. The method of claim 26, wherein providing the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the a top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the terminal, wherein the terminal includes selected portions of the conductive layers and the terminal contacts and extends above the dielectric layer.

33. The method of claim 26, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad and the terminal, wherein the pad and the terminal include selected portions of the conductive layers and the pad and the terminal contact and extend above the dielectric layer.

34. The method of claim 26, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer;

then

etching the conductive layers using an etch mask that defines the pad, wherein the pad includes selected portions of the conductive layers and the pad contacts and extends above the dielectric layer; and

etching the base using an etch mask that defines the terminal, wherein the terminal includes a selected portion of the base that is spaced and separated from and no longer a part of the base and the terminal contacts and extends below the adhesive.

35. The method of claim 26, wherein providing the conductive trace includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at the top lateral surface;

then

drilling a hole through the adhesive, the conductive layer and the dielectric layer;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer and into the hole, wherein a via includes a portion of the second conductive layer that extends through the adhesive and the dielectric layer in the hole; and

then

providing the pad and the terminal, wherein the pad includes selected portions of the conductive layers and extends above the adhesive and the dielectric layer, the terminal is coplanar with and has the same thickness as the base and extends below the adhesive and the dielectric layer and the conductive trace includes the pad, the terminal and the via.